A developing cartridge attachable to an electro-photographic type image forming apparatus is known in the prior art. The prior art discloses a developing cartridge including a developing roller, and a developing electrode made from electro-conductive resin.
Upon attachment of the developing cartridge to an image forming apparatus, the developing electrode is in contact with an electrode at the image forming apparatus side. Thus, electric power can be supplied from the image forming apparatus to the developing roller through the developing electrode.